On Tue, Jun 11, 2013 at 3:11 PM, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
There was some confusion on IRC as to whether bitcoin addresses are opaque or not.

https://en.bitcoin.it/wiki/Address

For the sake of argument let's say that opaque means that you can tell nothing about the address by examining the characters.

My understanding was that they are NOT opaque, and that if that has changed, it will invalidate much at least some wiki page, for examples at least some of the following would now be false:

How do you define opaque? As far as humans are concerned the addresses are opaque. They don't tell anything about your country or location, your bank, your name, they don't even form some kind of hierarchy.

From the viewpoint of the code you could argue they have a meaning "address type + hashed public key, base58 encoded" thus are not fully opaque. But it's a long shot, as a hashed value is still very opaque.
 
I also here that there is a LIKELY change from the base58 encoding ... when was this established?  

No, there have been no changes to base58. The encoding is still exactly the same as when Satoshi coined it. Can you show an example of what you mean?

Wladimir